Ground calcium carbonate for rare earth separation and saponification and preparation method of ground calcium carbonate

Abstract

The invention discloses ground calcium carbonate for rare earth separation and saponification and a preparation method of ground calcium carbonate. The ground calcium carbonate for rare earth separation and saponification is characterized in that the acid non-soluble substance content is smaller than or equal to 0.5%, the effective calcium content is larger than or equal to 98.5%, whiteness is larger than or equal to 95%, fineness range D97 is 2-20micron adjustable narrow particle size distribution, specific surface area is larger than or equal to 1.5m<2> / g, and an oil absorption value is smaller than or equal to 40mL / 100g. The parpearation method of the ground calcium carbonate includes raw ore crushing, dry grinding, grading, deironing, wet grinding, drying, secondary grading, tertiary grading, secondary deironing and depolymerization. The ground calcium carbonate for rare earth separation and saponification has advantages of high purity, low silicon, low ferro-aluminum, ultra-fineness, large specific surface area and narrow particle size distribution, the problem of exceeding of ammonia nitrogen ion and sodium ion contents in wastewater can be solved while occurrence of a thirdphase at an organic phase and aqueous phase interface is effectively inhibited, organic phase loss is reduced, production cost is saved, rare earth separation efficiency can be improved, and requirement of a novel rare earth extraction process can be well met.

Description

technical field [0001] The invention relates to a heavy calcium carbonate for rare earth separation and saponification and a preparation method thereof, belonging to the technical field of fine chemicals. Background technique [0002] At present, ammonia saponification or sodium saponification is commonly used in China for the extraction and separation of rare earths. The saponification wastewater produced by the ammonia saponification rare earth extraction and separation industry has the highest proportion in the rare earth extraction and separation industrial wastewater discharge, accounting for 60% to 70%. material resources, and caused great damage to ecology and the environment. The sodium soap method is to use sodium hydroxide instead of ammonia to saponify the acidic extractant. Although the sodium soap method has eliminated the pollution of ammonium chloride, it has produced sodium chloride pollution. It still does not fundamentally solve the problem of saponificati...

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Problems solved by technology

[0004] However, the use of calcium carbonate in rare earth saponification has encountered many problems, including: the third phase is prone to appear at the interface between the organic phase and the aqueous phase, silicon impurities increase the loss of the organic phase, and the purity of the rare earth product is easily affected by impurities in calcium carbonate. is trivalent Al 3 + , Fe 3+ Effect of ions

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